#define _CRT_SECURE_NO_WARNINGS 1
class Solution {
public:
    int search(vector<int>& nums, int target) {

        int right = nums.size() - 1;
        int left = 0;

        while (left < right)
        {
            int mid = (left + right) / 2;
            if (nums[mid] > target)
            {
                right = mid - 1;
            }
            else if (nums[mid] < target)
            {
                left = mid + 1;
            }
            else
            {
                return mid;
            }
        }

        if (right == left && nums[right] == target)
        {
            return right;
        }

        return -1;

    }
};